I made my first all grain beer recently and I like it but I have been troubled over the efficiency results I was given by Beertools. I hope the results are correct, but I would like to run them by someone with more experience.
The method I used was to soak my grain and amylase enzyme in a kettle as I brought it 157-160F and then let it rest for 60 min. I then strained the wort through a cheese cloth and a colander, returning the grain to the kettle and refilling the kettle with water. I then brought the temperature to 165-170 and let that rest for 60 min.
I then added the new wort to the first and the total came to around 6 gal. I then returned the the wort to the kettle. The combine wort had a hydrometer reading of 1.046. I didn't figure it would work past 1.012 and I wanted at least 5% ABV, but I was not concerned because I figured enough water would evaporate during the boil. At the end of the boil I took a hydrometer reading and the result was 1.055. I cooled the sample liquid prior to taking the reading, so I trust the result.
The finished results were as follows:
Recipe Type All Grain
Batch Size 5.46 gal
Measured Original Gravity 1.055 @ 60 F
Corrected Original Gravity 1.055
Measured Terminal Gravity 1.013 @ 60 F
Corrected Terminal Gravity 1.013
Mash Efficiency 88.2 %
Total Grain/Extract 10.00 lbs
Calories (12 fl. oz.) 182.7
6 lbs Munich 2RS Malt; Castle Malting info
2 lbs Melanoidin Malt info
2 lbs Peat Smoked Malt info
1 oz Perle (Pellets, 7.5 %AA) boiled 35 min. info
1 tsp. Amylase enzyme (not included in calculations)
Yeast : Lallemand 3767 Nottingham info

The 88.2% efficiency has me questioning myself, but the wort was as sticky as extract kits that I have used in the past, so 1.055 does not seem unreasonable. I just have a hard time believing my crude methods could result in that high of efficiency, but then again I used the amylase enzyme, so maybe that helped. Do you think?

I calculate 86% efficiency but that's quibbling. Just for perspective, I would usually get ~87% efficiency for a beer this size, so the numbers are not unreasonable.

Are the volumes accurate? That's important to getting accurate efficiency numbers. I'm a little skeptical about the 6 gallons boiling down to 5.5 gallons. 0.5 gallon evaporation would be fine, but less than most people would see. Also, the volume x gravity before the boil should equal the volume times gravity after the boil.

Your method may seem crude, but there is nothing inherently wrong with it that would lead you to expect lower efficiency. If you are confident in your measurements, then I think it was just successful.

A couple points:
You probably don't need to add enzyme. That might be why your efficiency was so good, though, I suppose.
You shouldn't need to let the second water addition sit for an entire hour. You are really just rinsing sugars during the sparge. It is possible that you might have continued to have some conversion during that time, though, pushing your numbers higher, especially with the warmer conditions. 10-20 minutes would probably be more than enough, though.